1. Field of the Invention
The present invention relates to a fluid apparatus such as a bellows type pump, a diaphragm type pump, or an accumulator.
2. Description of the Prior Art
As a pump for circulating and transporting chemical liquids in various processes such as washing of surfaces of ICs or liquid crystal display devices in a semiconductor producing apparatus, used is a bellows type pump or a diaphragm type pump in which no particles are generated as a result of the pumping operation (for example, Japanese Patent Publication Laying-Open No. 3-179184). Many of such chemical liquids are mixtures of two or more different kinds of liquids. Mixing of such chemical liquids is performed by transporting two or more different kinds of liquids from different chemical liquid tanks to a mixing tank or a processing tank and then circulating the liquids, or by pouring such different kinds of liquids into a processing tank by different liquid pumps.
In the case where such a mixture of two or more kinds of liquids is used, it is important that the concentration of the liquid mixture is uniform and constant. In a process of uniformly mixing two or more kinds of liquids, when mixture is attained by circulating the liquids for a constant time period, however, the process requires an excessively long time period. It has been requested to solve this problem. When a stirring tank is separately disposed, the scale of the liquid circulating line is enlarged. This is not preferable.
The present invention has been conducted in order to solve the problems. It is an object of the invention to provide a fluid apparatus such as a pump or an accumulator which can exert functions of stirring and mixing two or more kinds of chemical liquids in a liquid chamber of the pump or the accumulator, so that a uniform liquid mixture can be rapidly obtained.
The fluid apparatus of the invention will be described with reference to the drawings. The reference numerals in the figures are used in this paragraph in order to facilitate the understanding of the invention, and the use of the reference numerals is not intended to restrict the contents of the invention to the illustrated embodiments.
As exemplarily shown in FIG. 1, the fluid apparatus of the invention is a fluid apparatus configured by a reciprocating pump in which a barrier membrane 7 such as a bellows or a diaphragm that is reciprocally moved in an axial direction is disposed in a pump body 1 so as to form a liquid chamber 9 between the barrier membrane and an inner wall of the pump body 1, a suction port 18 and a discharge port 19 are disposed in the inner wall 4a of the pump body 1 facing the liquid chamber 9, and a stroke of sucking two or more different kinds of liquids from the suction port 18 into the liquid chamber 9 by reciprocal motion of the barrier membrane 7, and a stroke of discharging the liquids in the liquid chamber 9 from the discharge port 19 are alternately performed. In the pump, an outlet portion 18a of the suction port 18 facing the liquid chamber 9 is opened so as to eject sucked liquids toward an inner peripheral wall 9a of the liquid chamber 9, the inner peripheral wall being located in a direction different from the axial direction, and supply pipes 5A and 5B respectively for the two or more kinds of liquids are pipe-connected to an inlet portion of the suction port 18 so as to join together.
In this case, in place of the means for supplying the two or more kinds of liquids to the pump in which the supply pipes 5A and 5B for the respective two or more kinds of liquids are connected to the inlet portion of the suction port 18 so as to join together as described above, as shown in FIG. 7, inflow paths 5 respectively for the two or more kinds of liquids may be individually disposed in the pump body 1, and outlets of the inflow paths 5 may be communicatingly formed in the inlet portion of the suction port 18 so as to join together in the inlet portion.
An outlet portion 18a of the suction port 18 may be disposed in a side face of a protruding forward end of a suction check valve 20 which is fixed to protrude from the inner wall 4a of the pump body 1 facing the liquid chamber 9, into the liquid chamber 9.
According to the thus configured fluid apparatus, since the outlet portion 18a of the suction port 18 is opened so as to eject the two or more kinds of sucked liquids toward the circumferential wall in the liquid chamber 9 which is located in a direction other than the axial direction, the two or more kinds of sucked liquids are ejected from the outlet portion 18a of the suction port 18 so as to circulate along the inner periphery of the liquid chamber 9. This circulating action exerts an effect of stirring the two or more kinds of sucked liquids. Therefore, the two or more kinds of liquids which are separately supplied to the pump are uniformly stirred and mixed in the liquid chamber 9.
As exemplarily shown in FIG. 5, the fluid apparatus of the invention is a fluid apparatus configured by an accumulator in which a barrier membrane 29 such as a bellows or a diaphragm that is reciprocally moved in an axial direction is disposed in an accumulator body 25 so as to form a liquid chamber 31 inside the barrier membrane, two or more different kinds of liquids being to flow into said liquid chamber, and an air chamber 32 outside the barrier membrane, an inflow port 23 and an outflow port 24 are disposed in an inner wall 28a of the accumulator body 25 facing the liquid chamber 31, and a liquid pressure in the liquid chamber 31 is balanced with an air pressure in the air chamber 32. In the accumulator, an outlet portion 23a of the inflow port 23 facing the liquid chamber 31 is opened so as to eject sucked liquids toward a circumferential wall of the liquid chamber 31, the circumferential wall being located in a direction other than the axial direction, and supply pipes 5A and 5B respectively for the two or more different kinds of liquids are pipe-connected to an inlet portion of the inflow port 23 so as to join together.
In this case, in place of the means for supplying the two or more kinds of liquids to the accumulator in which the supply pipes 5A and 5B for the respective two or more kinds of liquids are connected to the inlet portion of the inflow port 23 so as to join together as described above, inflow paths 33 respectively for the two or more kinds of liquids may be individually disposed in the accumulator body 25, and outlets of the inflow paths 33 may be communicatingly formed in the inlet portion of the suction port so as to join together in the inlet portion.
An outlet portion 23a of the inflow port 23 may be disposed in a side face of a protruding forward end of a discharge check valve 21 which is fixed to protrude from the inner wall of the accumulator body 25 facing the liquid chamber 31, into the liquid chamber 31.
Since the outlet portion 23a of the inflow port 23 is opened so as to eject the two or more kinds of inflow liquids toward the circumferential wall in the liquid chamber 31 which is located in a direction other than the axial direction, the two or more kinds of inflow liquids which are ejected from the outlet portion 23a of the inflow port 23 to circulate along the inner periphery of the liquid chamber 31. This circulating action exerts an effect of stirring the two or more kinds of sucked liquids. Therefore, the two or more kinds of liquids which are separately supplied to the accumulator are uniformly stirred and mixed in the liquid chamber.